Recently attempted to update a Microsoft Windows XP workstation only to encounter an error message, error 0x80240025. According to one forum, it could be that of a Group policy to disable access to the Windows update.

Error 0x80240025 denotes a Group Policy setting. If you check the registry for the DisableWindowsUpdateAccess key, you will likely find the following:

HKEY_USERS\S-1-5-18\Software\Microsoft\Windows\CurrentVersion\Policies\WindowsUpdate

S-1-5-18 maps to the SYSTEM ACCOUNT. To correct the problem, either set the value to 0 or delete the key. You may also need to check that you do not have a Group Policy that continues to set this value to 1 to avoid the problem from happening after a policy is refreshed.

DisableWindowsUpdateAccess REG_DWORD (1)

Tested, works.